The problems resulting from uneven temperature distributions across the bar length and cross-section increase with high finish-rolling velocities in modern wire and steel bar trains with large initial pass sections. In a multi-line train, floating or reciprocating finish velocities are additionally observed, resulting from the differing rolling stock cross-sections in the multi-line area of the train, which results in a rapid velocity regulation of the installation portions disposed behind the pilot stand. The difficulties can increase to such an extent that the finish-rolling velocity must be reduced. For rolling stock exiting from the pilot stand, its cross-section fluctuates because of the unavoidable longitudinal pull between the stands located upstream of the pilot stand. In this region, rising cross-sectional differences lie within a range of between a minimum and maximum value of approximately 5%. These cross-sectional differences are then largely compensated or equalized in the downstream single line intermediate train, leading however to velocity differences which must be reduced in particularly the case of high finish-rolling velocities.
It is therefore an object of the invention to improve a rolling mill for wire or bar steel to overcome, in a simple way, some of the difficulties and technical limits caused by uneven temperature distribution across the bar length and the bar cross-section and the varying finishing velocities.